British entrepreneur Richard Branson has joined the rush into the internet music arena.

He has launched a Virgin Digital music store in the US, offering tracks for 99 cents (55p) and subscription options. He plans to extend the service beyond the US, but no dates have so far been announced.

Virgin is one of the first major music retailers to enter an increasingly crowded online music market, dominated by Apple and other technology companies

'Growth potential'

Jupiter Research expects the online music market in the US to grow from around $100m (£55.5m) in 2003 to $1.7bn (£945m) in 2009.

The past year has seen a raft of music services launched in both the US and the UK. Companies such as Microsoft, Sony, RealNetworks and Coca-Cola have all set up online music stalls.

In the UK, the music chain HMV already offers an online music store.

But Virgin is confident that it can carve out a place in this crammed marketplace.

"We don't see this as crowded," said Zack Zalon, president of Virgin Digital.

"It's not saturated at all and there is tremendous growth potential," he told the Reuters news agency.